The Ferndale Police Department is denying allegations that it possibly engages in racial profiling after an American Civil Liberties Union study found the department ticketed a disproportionate number of black motorists.

The Daily Tribune of Royal Oak reports the study found about 60% of ticketed motorists near Detroit were black when the driver’s race was known. It analyzed thousands of tickets issued between January 2013 and May 2014. The ACLU says it’s investigating and wants more information from the department.